Electric furnace



M. R. TREMBOUR.

ELECTRIC FURNACE.

AFPLlCATlON FILED MAR: 24, 1916.

1,333,950. Y Patented Mar. 16, 1920.

2 SHEETS-SHEET I.

5. TREMBOUH; ELEGTRIC FURNACE. APPL ICATIGN HLED MAR.24, 19H}.

1 333,950. 39mm Mar, 16,1920.

- 2 SHEETS-SHEET 2.

UNITED Max 12.. TREMBOUR, or wnrnnvriar, roan, ASSIGNOE, BY MESNE assrenuznirrs,

'ro LunLuM unscrew roan-son conronarioir, or anemia, newsman, A conno- RATION OF NEW YORK.

ELECTRIC IEUBHACE.

Application filed. March 24., 1916.

ments in Electric Furnaces, of which the following is a specification.

I My invention relates to electric furnaces, and the object of my invention is to provide a furnace adapted for operation at a minimum cost; together with such elements and combinations as are hereinafter more particularly set forth and claimed.

accomplish these objects by means of the mechanism illustrated in the accompanying drawings, in which:

Figure 1 is a plan.

Fig. 2 is a section along the lines, cit-40,

on Fig. l. q

.Fig. 3 is a section along the lines, b?), on Fig. 1.

Fig. 4 is a plan of amodified form of my invention.

Fig. 5 is a section along the lines, o e, on Fig. 4.

Fig. 6 is a section along the lines, d-ai,

on Fig. 4. i

Fig. 7 is a vertical section of my izurnace showingthe rocker for tilting same.

Fig. 8' is an end view of the furnace with the door removed.

Fig. 9 is a side elevation showing the furnace tilted in the act of pouring.

Similar letters refer to similar parts throughout the several views.

The cost of operating anelectric furnace depends mainly upon two factors:

(1) The life of the refractory furnacelining and roof and its a'ccessJoihty for quick repairs, removal and replacement.

(2) The electric power consumption.

Both of these factors are determined by the design of the furnace-chamber, as well as by the arrangement l of the electrodes, upon which depends the osition of the electric arcs in the chamber relative to its walls, roof and doors and to the metal charge.

For the design of the furnace-chamber the following rules may be considered fundamental; -1 v Simplicity and strength in construction, avoiding all sharp turns, breaks and open- Specification of Letters 3.atent.-

hatenteol Mar. 36, E921).

Serial. no. 88,418.

ings as far as possible without impairing .easy accessibility of all parts of the furnacechamber, and smallest possible surface of chamber walls, relative to its metal charge, so as to confine the heat and prevent excessive loss by radiation. Q

frleretofore the chambers of electric are furnaces have been constructed substantially from rectangular to circular in their horizontal as well as in their vertical sections. The electrodes, wherever more than two were used, were accordingly arranged in triangle or square groups around the center of the furnace. This construction necessitated very large or very numerous doors so as to admit access for observation and repairs to allparts of the chamber. Also, as a rule, a special door or spout was provided to pour off the charge. W' hen tilting a furnace of this construction, the wall opposite the spout must necessarily overhang, which often results in its caving in.

A furnace of spherical design presents admittedly the least possible surface relative to its bulk. It does not do so, however, relative to its melting capacity, there being tech nical limits to the depths of the metal bath,

' which in a spherical furnace will form only a small segment of the circle representing the vertical. section of the furnace chamber. 1 have found that a greater economy in operation results, when the chamberof an arc-furnace is oblong, with the doors used for charging and pouring both at the ends of the longer axis of the furnace and the electrodes arranged substantially on this same axis, the furnace being tilted about its shorter axis.

The accompanying drawings illustrate in principle the construction of the furnace chamber and the arrangement of the electrodes; also the contours of the metal bath and the position of the arcs relative to the bath and to the chamber walls.

'llhe furnace comprises a steel shell, 0, lined with lire brick or other refractory material, 1, and hung upon trunnions \or set upon rockers, 9, upon which it is adapted to be tilted for pouring out the charge of metal.

The turtlc-baclr-shaped roof, 2, is provided troduce the charge, to rve the condition of the charge when operating, and to pour out the melted slag and lllnllfll.

The drawings also illustrate electrode-adjustrnents for a variety or melting and fining processes, for which the 'li'urnacc is suitable. 1, 2 and 3 ilustratc the lining process in a cord nce with the method described in a co-pcnd1ng application, and for which this furnace is especially rcco1n-- mended. This turnace, as will be seen from the drawings, is provided with two parallel rows of electrodes, which arrangement would be advisable for furnaces of very large capacity. The electrodes, l and 6, arc spaced away from the slag, 8, and are arcing, while the central electrodes, 5, are contact ing with the metal, 7, without arcing.

Figs. 4, 5 and 6 illustrate a furnace with one row of three electrodes, all of which are spaced away and are to the melted bath, 7.

l have shown in 5 a. furnace equipped with the water-cooled metal electrodes, 10, introduced through the bottom of the furnace and contacting with the metal, ,although I may use arrangement of electrodes in the furnace illustrated in F lgs. 1, 2 and 3, which is without the Water-cooled metal electrodes.

As will he seen from these drawings, the form of the furnace ch: rnloer is in general ovoid, or ellipsoidal, all its walls lilting curved. There are no perperlicular sidewalls, no exposed sharp corners and breaks in the lining. The surface of the chamberwalls relative to the charging tonnage (melting capacity) is small, all vertical sections of th chamber, longitudinal as well as lateral, approaching the elliptic form instead of the square or circular. The chain her tapering from its widest lateral cross-- sections near both ends, leads to the naturallocation of the doors at these ends, insuring easy accessibility to each part of the cham her. The position of the doors at each end of the furnace and parallel to the tilting aXis is a decidedadvantage in charging Well as in pouring the metal, as either door can he used for pouring and can at once he brought into the most convenient position charging. T here being walls parallel to the tilting axis, no part of the lining can. overhang and cave in when the furnace is tilted. (See Fig. 9.)

As the electrodes are arranged along the longer axis, the heat will be generated as liar away as possible from the refractory lining" and roof of the furnace and at the same time along a line, below which the metal hath. reaches its greatest depth. in other words, the heat will be applied to the metal instead oi to the refractory lining.

lVhat claim as my invention and desire to secure by Letters l atcnt is:

An electric furnace having melting health of generalovoid shape in plan wi. dished hot-tom constricted toward the opposite ends of its major axis, doors at the opposite ends of said inajor axis for cos .ing and discharging the furnace and th ou wl'i-ich access to the interior may he ha repairs, a removable low arched roof of eral like out-line as the hearth. and havin the opposite ends of its major axis completing the door openings of the :7 7 together with vertically adjustah piercing the roof and arrang major axis of the furnace, the c hearth lacing predetermined withvrelation the location the electrodes to afford least practical surface compared to the 1 ing capacity of. the furnace and toconinie heat, prevent radiation loss and insure an even distribution of heat throughout tire hearth. area, the greatest heat being germ erated at the point of greatest depth of melt on the hearth,

2, ln a construction such as specific in claim 1, a hearth bottom having an inc tion of less than 45 from mid area the door openings to permit the free discharge the melt when. furnace is rocked through a relatively small An electric furnace having a heat. general ovoid shape and dished bottom doors at the opposite ends of its ina i low arched root meeting sides s hearth and conforming in general outl the outline oi. the hearth and having 5 opposite ends a lire-brick lining compile-1c a. series of transverse parallel arches lerent radii, the terminal arches of radius cooperatingwith the hearth ends to complete the ends of door openings or" the i ornace, substantially as descrihed.

l. An electric furnace having a m lt" hearth of general ovoid shape in plan a dished hottorn constricted toward the or, site ends of its major axis and flattened in longitudinal section through. mid removable roof therefor conforming; in eral outline to the outline of the hearth having a similarly flattened mid ares cally registering with that of the he; combination with vertically adjustalne trodes piercing the flattened mid area of the roof and overlying the corresponding area of the hearth, said area of the, hearth sun-- porting tie molten charge at its deepest point and therewith insijiring the generation of the greatest heatat the point at which metal hath is of the greatest depth,

5. An electric-arc furnace comprising an elongated hearth lined with. refractory ma, terial, forming at each end of the loneltudina .cis of the hearth, the sill and sides of a charging or discharging opening, the inner side of said hearth tapering in opposite directions in general ovoid form toward said openings respectively; and an archcdlessees site directions in general ovoid form toward said openings respectively; an arcl'zed-rooff detachably mounted upon said hearth, an

having a lining of refractory brick forming roof-arches for said openings respectively; means whereby said furnace can he tilted upon anaxis at right angles to its longi tudinal axis; doors for closing said openings respectively; and a plurality of electrodes inserted through said detachable roof along the longer axis of the furnace.

In testimony whereof l. have atiixed. my signature in presence of two Witnesses.

MAX TREMBOUlrl. 

